140 Part III. — Twenty-second Annual Report 



Fig. 56. Egg of Homarus imlgaris, showing throe attachments, . . x 10 



Fig. 57. Egg of Homarus vulgaris, showing tliree attachments. 



Fig. 58. Tip of liair of endopodite of Homarus vulgaris. 



Fig. 59. Dissection of first penis, magnified. 



Fig. 60. Longitudinal section of first penis, semi -diagrammatic, to show 



the relationship of first and second penes and the genital 



papilla, magnified. 

 Fig. 61. Longitudinal section of second penis, to show muscles seen from 



median line. 

 Fig. 62. Tip of endopodite, posterior surface, magnified. The hairs ought 



in proportion to be larger (viz., about one-third longer) 



than they are here represented. 

 Fig. 63. Plan of a row of hairs of endopodite, magnified. 



Fig. 64. Hair of endopodite of Neplirops norvegicus, . . . x 48 



Fig. 65. First and second penes, lateral (external) view. 

 Fig. 66. Muscles of second penis. 



Fig. 67. Spermatheca of hard crab, 6| inches. December 1st, 1899. 

 Fig. 68. Second penis, lateral (external) view. 

 Fig. 69. First penis, lateral (external) view, shows relationship of genital 



papilla. 

 Fig. 70. External (attached) egg of Ca)'CJjm«wi(Mia5. December 21st, 1897. 



Plate IV. 

 Figs. 94, 95, and 96 were outlined by means of the camera lucida. 



Figs. 71-81. Successive casts of a Cancer pagioi'us, Nos. 2-12 inclusive, 

 viz.. A, Table VI. Natural size. 



Figs. 82-93. Successive casts of a Carcinus ananas, viz.. No. 1 in 

 Table I. in " On the Larval and Early Young Stages, and 

 Rate of Growth, of Carcinus mcenas." Twenty-first Annual 

 Report of the Fishery Board for Scotland, Pt. III., p. 166. 



Fig. 94. Egg of Cancer pagurus taken from the vagina of a spawning 



female by means of a pipette, 30/11/00, . . . x 57 



Fig. 95. Egg just extruded, . . . . . . . x 57 



Fig. 96. Egg found on Ijottom of tank beside a spawning Cancer pagurus, x 57 



Plate V. 



The figures in this plate, with the exception of Fig. 100, were outlined by means 

 of the camera lucida. 



Fig. 97. Edge of carapace of the cast represented in Fig. 75, . . x 19 



Fig. 98. Half of carapace do. do. 74, . . x 19 



Fig. 99. Frontal region do. do. 75, . . x 19 



Fig. 100. Cast chela of a Cancer pagurtis to show the absorption lines 



(abs.) on [the coxopodite, basi-ischiopodite, and meropodite 



joints. Natural size. 

 Fig. 101. Half of cai-apace of the cast represented in Fig. 72, . . x 19 



Fig. 102. Do. do. do. 73, . . x 19 



Fig. 103. Enlarged drawing of cast shell represented in Fig. 71, carapace, x 19 

 Fig. 104. Joint on second penis, Cancer pagurus. 

 Fig. 105. Tip of second penis, do. 



N.B. — The " arrows" which accompany certain of the figures serve to indicate 

 the anteroposterior median line ; the point of the arrow is directed anteriorly. 



